Improvement of speckle noise reduction using multi-resolutional coherence measurement in ultrasound image

Ultrasound (US) images are degraded by speckle noise that reduces the contrast and details of images. But the effective method for speckle noise reduction with keeping edge has been still a challenging point. Coherence measurement has been used to distinguish homogeneous region and coherence regions, e.g. edges, and the edge map obtained from coherence measurement has limitation such as noisy or discontinued edge detection. In this paper, to overcome these problems, the enhanced edge map generation using multi-resolutional coherence measurement is proposed and adaptive wavelet based-speckle noise reduction is performed using the enhanced edge map. The experimental results showed that the enhanced edge map by proposed method contains the robust and linked edge information. Moreover, the results show that the proposed method outperforms the conventional method in preserving edge details.